Different cooling systems are known in the art of the refrigeration. Thus, for example, it is known that the air temperature within a refrigerator must be at 3.degree. C., which means low levels of the air humidity. In the case of a refrigerator without frost formation (No-Frost) the air circulates from the refrigerator compartment to the evaporator and returns to the refrigerator compartment. The effect of this air circulation, upon passing through the evaporator, which is normally at a temperature well below 0.degree. C., is that it captures the air humidity condensating it in the evaporator and leaves the air returning to the refrigerator very dry. This dry air dehydrates the food contained in the refrigerator and thus a refrigerator that does not dehydrate food must have a cooling system in which the air does not pass to the evaporator in order to avoid getting to temperatures below 0.degree. C. A technique to reach this objective is to manufacture a refrigerator with separated compartments and to equip the freezer with an evaporator and the refrigerator with a cold plate. This solution to the problem of drying food is correct but it has the drawback of being highly complex and costly.
Among other known systems, there is the one of the condensation in the frame of the refrigerator door such as the one described in U.S. Pat. No. 4,192,149, in which a refrigerator cabinet is claimed which includes a chamber divided by a mullion between the freezer and the fresh food compartment and each chamber has a front part opened towards the door frame that prevents the condensation of the system.
In U.S. Pat. No. 4,250,719, the assembly of a panel in the refrigerator compartment with controlled humidity is described, said assembly includes a storage container with an open upper part and a stationary lid inside the refrigerator to receive the container, and a control mechanism. Through this arrangement, the user can move said mechanism to increase or diminish the amount of ventilation and thus control the humidity inside the container. As can be observed, said control is manual.
In U.S. Pat. No. 4,729,613, a modification of the previous patent is described, in which an assembly of container in two removable sections for fresh food within a rigid unitary frame is claimed.
The applicant has developed a new cooling system through a contact duct which is applied to the functioning of a two-door and two-compartment refrigerator with independent temperature regulation between the two compartments, refrigerator and freezer. The compartments are separated and the air is not mixed. Thus, the refrigerator compartment dehydrates less the food contained in it.
There is also the air circulation system without mixing the air between the two chambers, as would be the case of the two evaporators used on the European market. Said system of two evaporators is the one which is nearest to the objective of not dehydrating food in the refrigerator compartment, but it is a more expensive system.
Hereinafter, the invention will be described with reference to FIGS. 1 to 3.